213 ASSESSMENT OF THE SUSCEPTIBILITY OF PORCINE PRE-IMPLANTATION EMBRYOS TO PSEUDORABIES VIRUS (PRV) AND PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME VIRUS (PRRSV) USING SUBZONAL MICROINJECTION

2006 ◽  
Vol 18 (2) ◽  
pp. 214 ◽  
Author(s):  
B. Mateusen ◽  
A. Van Soom ◽  
D. Maes ◽  
H. Nauwynck

It is known that porcine pre-implantation embryos before the morula stage are refractory to infection with pseudorabies virus (PRV) and porcine reproductive and respiratory syndrome virus (PRRSV) (Bolin et al. 1981 Am. J. Vet. Res. 42, 1711-1712; Prieto et al. 1996 Theriogenology 46, 687-693, respectively). The effects of PRV and PRRSV on embryonic cells of morulae and blastocysts are unknown. Therefore, the objectives of the present study were to (1) assess the effects of PRV and PRRSV exposure on further embryo development, and (2) determine whether PRV and PRRSV are able to replicate in embryonic cells. Zona pellucida (ZP)-intact morulae (6 days post-insemination, 6 dpi) and early blastocysts (7 dpi) were microinjected subzonally with approximately 3 nL of 109 TCID50/mL PRV (strain 89v87, second passage in swine testicle cells) or 108.6 TCID50/mL PRRSV (Lelystad virus strain, 13th passage in swine alveolar macrophages). Control embryos were microinjected under the same circumstances with phosphate-buffered saline (PBS). Hatched blastocysts (8 dpi) were exposed for 1 h at 39�C to 105 TCID50/mL of PRV or PRRSV of the same strains used for injecting earlier embryonic stages. Control hatched blastocysts were incubated with PBS. Each group of morulae and blastocysts consisted of approximately 20 embryos. Embryonic development was assessed every 12 h. At 48 h post injection, the percentage of infected embryos and the percentage of viral antigen positive cells per embryo were determined by immunofluorescence. Subzonal microinjection of ZP-intact morulae and blastocysts with PRV inhibited in vitro development in comparison to the controls. Moreover, under direct immunofluorescence, PRV antigen-positive cells were detected in association with the embryos. Exposure of hatched blastocysts to PRV inhibited further embryo development; the majority (16/20) of the embryos degenerated 24 h after incubation. Perivitelline microinjection of ZP-intact morulae and blastocysts with PRRSV and incubation of hatched blastocysts with PRRSV did not inhibit in vitro development in comparison to the controls. No PRRSV antigen positive cells were detected in association with the embryos. Based on these results, it can be deduced that embryonic cells of morulae and blastocysts are susceptible to PRV infection but refractory to PRRSV infection. Another argument substantiating insusceptibility of embryos to certain viral pathogens is the demonstration of the lack of virus receptors at a given embryonic cell stage. Therefore, the expression of sialoadhesin, the receptor that mediates the internalization of PRRSV in cells, was investigated in hatched blastocysts (n = 10). By indirect immunofluorescence using monoclonal antibody 41D3 directed against porcine sialoadhesin, no positive signals were detected. The result of this experiment strengthens the statement that embryonic stages up to the hatched blastocyst stage are refractory to PRRSV infection.

2004 ◽  
Vol 16 (2) ◽  
pp. 219
Author(s):  
B. Mateusen ◽  
A. Van Soom ◽  
D.G.D. Maes ◽  
H.J. Nauwynck

Porcine preimplantation embryos are refractory to infection with pseudorabies virus (PRV) and porcine reproductive and respiratory syndrome virus (PRRSV) during the 2–4 to 16-cell stage as described by Bolin et al. (1981 Am. J. Vet. Res. 42: 1711–1712) and Prieto et al. (1996 Theriogenology 46: 687–693), respectively. Research on the effects of PRV and PRRSV on embryonic cells of morulae, blastocysts and hatched blastocysts is limited. Therefore, the objectives of the present study were (i) to assess the effects of PRV and PRRSV exposure on further embryonic development, and (ii) to determine whether PRV and PRRSV are able to replicate in embryonic cells of porcine morulae and blastocysts. In vivo produced ZP-intact and ZP-free morulae (6 days post-insemination), early blastocysts (7 days post-insemination), and hatched blastocysts (8 days post-insemination) derived from 22 superovulated sows were exposed to 105 TCID50 PRV (strain 89v87, second passage in swine testicle cells) or to 105 TCID50 PRRSV (Lelystad virus strain, 13th passage in swine alveolar macrophages) for 1h at 39°C. Control embryos were incubated under the same circumstances without viruses. Each group of morulae and blastocysts consisted of approximately 20 embryos. Embryonic development was assessed every 12h and differences in rates of development were analyzed using Chi-square analysis or Fisher’s exact test. At 48h post-incubation, embryos were collected and examined for viral antigen by indirect immunofluorescence. Further embryo development of ZP-intact and ZP-free morulae and blastocysts was not affected by exposure to PRV or PRRSV compared to controls (P<0.05). Moreover, using indirect immunofluorescence, no PRV or PRRSV antigen-positive cells were detected. Exposure of hatched blastocysts to PRV inhibited further embryo development as 100% (n=5) of the embryos degenerated 24h after viral exposure. This was significantly different (P<0.05) from the controls and the PRRSV-incubated hatched blastocysts that did not experience any negative influence on embryo development. Based on these results it can be concluded that embryonic cells are not susceptible to a PRRSV infection up to the hatched blastocyst stage. Embryonic cells of morulae and blastocysts are refractory to PRV, but the virus has a detrimental effect on further embryo development of hatched blastocysts. More experiments are necessary to confirm these results and to investigate whether, or at which preimplantation stage, embryos are susceptible to a PRRSV infection.


2011 ◽  
Vol 23 (1) ◽  
pp. 199
Author(s):  
T. Somfai ◽  
K. Imai ◽  
M. Kaneda ◽  
S. Akagi ◽  
S. Haraguchi ◽  
...  

The aim of the present study was to investigate the effect of oocyte source and in vitro maturation (IVM) on the expression of selected genes in bovine oocytes and their contribution to in vitro embryo development. Follicular oocytes were collected either by ovum pick-up from live cows or by the aspiration of ovaries of slaughtered cows following storage in Dulbecco’s PBS at 15°C for overnight. In vitro maturation was performed according to the method of (Imai et al. 2006 J. Reprod. Dev. 52, 19–29 suppl.). Gene expression was assessed before and after IVM by real-time PCR. The following genes were investigated: GAPDH, G6PDH, ACTB, H2A, CCNB1, MnSOD, OCT4, SOX2, CX43, HSP70, GLUT8, PAP, GDF9, COX1, ATP1A1, CDH1, CTNNB1, AQP3, DYNLL1, DYNC 1/1, and PMSB1. In brief, mRNA was extracted from 20 oocytes per sample using a Qiagen RNeasy Micro Kit (Qiagen, Valencia, CA). Gene expression was analysed by a Roche Light Cycler 480 device and software (Roche, Indianapolis, IN). Relative expression of each gene was normalized to CCNB1, which in preliminary experiments appeared the most stably expressed irrespective of oocyte source and meiotic stage. Three replications were performed. Data were analysed by paired t-test. In immature ovum pick-up oocytes, genes related to metabolism (GAPDH, G6PDH, GLUT8) and stress (MnSOD, HSP70), and also OCT4, ATP1A1, and DYNC1/1 showed significantly (P < 0.05) higher expression compared with immature oocytes collected from slaughtered-stored ovaries. The expression of GDF9, GLUT8, CTNNB1, and PMSB1 was significantly (P < 0.05) reduced during IVM irrespective of the oocyte source. In a second experiment, IVF IVM oocytes showing an early (at 22 to 25 h after IVF) or late (at 27 to 30 h after IVF) first cleavage were either cultured in vitro or analysed for gene expression at the 2-cell stage. A higher (P < 0.05) rate of early-cleaving oocytes developed to the blastocyst stage compared with the rate of late-cleaving ones (46.2% v. 15.6%, respectively). Nevertheless, only ATP1A1 showed significantly reduced (P < 0.05) expression in late-cleaving embryos compared with early-cleaving ones. Our results suggest that although removal and storage of ovaries and IVM caused a reduction in the relative abundance of several genes in oocytes, in most cases, this did not affect embryo development. Among the genes studied, only ATP1A1 was correlated with in vitro development.


2006 ◽  
Vol 18 (2) ◽  
pp. 187
Author(s):  
J. De la Fuente ◽  
A. Gutiérrez-Adán ◽  
P. Beltrán Breña ◽  
S. S. Pérez-Garnelo ◽  
A. T. Palasz

It is assumed that, contrary to phosphate buffers, zwitterionic buffers are neutral. However, zwitterionic buffers containing hydroxymethyl or hydroxyethyl residues may interact with OH-groups in the media and produce formaldehyde (Shiraishi et al. 1993 Free Radic. Res. Commun. 19, 315-321). Also, it was shown that three zwitterionic buffers tested in this study interact with DNA (Stellwagen et al. 2000 Anal. Biochem. 287, 167-175). Our objective was to evaluate the effect of the following buffers: TES (T), MOPS (M), HEPES (H) (pKa values at 20�C: 7.2-7.5), and PBS on in vitro development and morphology of bovine embryos. Zwitterionic buffers and PBS were prepared at a concentration of 10 mM in TALP medium and the final pH was adjusted to 7.2. Bovine follicular fluid was aspirated from abattoir-derived ovaries and evenly divided into four tubes. Collected oocytes (five replicates) from each tube were processed separately through the entire IVM, IVF, and IVC procedures using washing medium buffered with: PBS (n = 490), Group 1; H (n = 438), Group 2; M (n = 440), Group 3; and T (n = 394), Group 4. All buffers contained 4 mg/mL BSA. Oocytes were matured in TCM-199 + 10% FCS and 10 ng/mL of epidermal growth factor and fertilized in Fert-TALP containing 25 mM bicarbonate, 22 mM sodium lactate, 1 mM sodium pyruvate, 6 mg/mL BSA-FAF, and 10 �g/mL heparin with 1 � 106 spermatozoa/mL. After 24 h, oocytes-sperm co-incubation presumptive zygotes were cultured in SOFaa medium with 8 mg/mL BSA at 39�C under paraffin oil and 5% CO2 in humidified air. Cumulus-oocyte complexes and zygotes were held in designated buffers ?16 min before oocyte maturation, ~7 min after IVM and before IVF, and ~18 min after IVF and before culture. The total time of oocyte/embryo exposure to each buffer was ?41 min. Embryo development was recorded on Days 4, 7, 8, and 9. A total of ten, Day 8 blastocysts were taken randomly from each treatment and fixed in 4% paraformaldehyde for total and apoptotic cells counts, and five blastocysts from each replicate and treatment were frozen for later mRNA analysis. Apoptosis were determined by TUNEL, using commercial In situ Cell Death Detection Kit (Roche Diagnostic, SL, Barcelono, Spain). Embryo development among groups was compared by chi-square analysis. The cleavage rates were not different among the groups: PBS, 70.8%; H, 76.5%; M, 77.5% and T, 73.6%. The number of embryos that developed to d8 cells at Day 4 was higher in M, 36.2%, and PBS, 37.6%, than in H, 30.6%, and T, 29.7%, but was not significantly different. However, more (P < 0.05) blastocysts developed at Days 7, 8, and 9 in H and M than in PBS and T groups (21.9% and 22.9% vs. 16.9% and 14.9%, respectively). No difference was found between groups in total cell number (98.8 � 7, PBS; 111.8 � 11.9, M; 106.8 � 12.9, H; and 104.3 � 9.7, T) and the number of apoptotic cells (9.2 � 1.0, P; 9.2 � 0.8, M; 12.9 � 1.8, H; and 9.7 � 0.9, T). Based on the results of this study, we conclude that within our protocol choice of buffer may affect embryo developmental rates but not morphology.


2013 ◽  
Vol 25 (1) ◽  
pp. 174
Author(s):  
R. Olivera ◽  
C. Alvarez ◽  
I. Stumpo ◽  
G. Vichera

The time allowed for nuclear reprogramming is considered an essential factor for the efficiency of cloning and has not been evaluated in equine aggregated cloned embryos. The aim of our work was to assess the effect of different timing of activation stimulus after fusion of adult equine fibroblast cells to enucleated equine oocytes on embryo development and embryo quality. We processed a total of 1874 equine ovaries, recovering 3948 oocytes, of which 1914 (48.5%) had extruded the first polar body after 24 h of maturation. Oocyte collection, maturation, and the NT procedure were performed as described by Lagutina et al. (2007 Theriogenology 67, 90–98). Reconstructed oocytes (RO) were activated at 3 different times after cell fusion: (1) 1 h, (2) 1.5 h, and (3) 2 h. Activation was performed using 8.7 µM ionomycin for 4 min, followed by a 4-h culture in a combination of 1 mM DMAP and 5 mg mL–1 of cycloheximide. The RO were cultured in the well of the well system, aggregating 3 RO per well. The RO were cultured in DMEM-F12 with 5% fetal bovine serum (FBS) and antibiotics. Cleavage (48 h after activation), blastocyst, and expanded blastocyst rates (8–9 days) were assessed. In vitro development was compared using the chi-square test (P < 0.05). A total of 1608 RO were cultured. Cleavage was significantly lower in group 3 with respect to the other 2 groups [(1): 396/450, 88%; (2): 540/639, 84.5%; (3): 365/519, 70.3%]. There were no significant differences in blastocyst rates within the 3 groups considering the number of total RO [(1): 19/450, 4.2%; (2): 23/639, 3.6%; (3): 15/519, 2.9%] or aggregated RO per well [(1): 12.7%; (2): 10.8%; (3): 8.7%]. However, the rate of blastocyst expansion was higher (P < 0.05) in group 2 than in group 3 [(1): 17/19, 89.5%; (2): 23/23, 100%; (3): 11/15, 73.3%]. In conclusion, the timing of nuclear reprogramming did not affect blastocyst rates but affected cleavage rates and blastocyst quality. This indicates that 1 h before activation stimulus is enough for embryo development of equine aggregated cloned embryos.


2011 ◽  
Vol 23 (1) ◽  
pp. 124
Author(s):  
C. Feltrin ◽  
M. Machado ◽  
L. M. V. Queiroz ◽  
M. A. S. Peixer ◽  
P. F. Malard ◽  
...  

In vitro embryo production by handmade cloning (HMC) usually requires individual embryo culture, because zona-free embryos cannot be grouped in standard in vitro culture (IVC) protocols. The aim of this study was to evaluate the developmental potential of bovine embryos produced by HMC (Ribeiro et al. 2009 Cloning Stem Cells 11, 377–386) after in vitro culture (IVC) in 3 microwell (WOW) systems. After in vitro maturation, oocytes were denuded and incubated in demecolcine (Ibáñez et al. 2003 Biol. Reprod. 68, 1249–1258), followed by zona pellucida removal, oocyte bisection, embryo reconstruction, electrofusion, and chemical activation. Cloned embryos were allocated to 1 of 3 IVC groups: cWOW: conventional microwells (250 μm, round; Vajta et al. 2000 Mol. Reprod. Dev. 55, 256–264); mWOW: modified microwells (130 μm, conical; Feltrin et al. 2006 Reprod. Fert. Dev. 18, 126); and WOW-PDMS: microwells in polydimethylsiloxane chips (170 μm, cylindrical with microchannels); IVF embryos were used as controls (Bertolini et al. 2004 Reproduction 128, 341–354). Cleavage (Day 2), blastocyst (Day 7), and pregnancy (Day 30) rates were analysed by the chi-square test, for P < 0.05. Results are shown in Table 1. Cleavage rates were similar between groups, but development to the blastocyst stage was higher in IVF controls than cloned embryo groups. Among cloned embryo groups, blastocyst rate was higher in the mWOW group than the conventional and the PMDS-based microchannels. Nevertheless, in vivo development to Day 30 of pregnancy was not different between cloned groups. Our results for in vitro embryo development indicated that the mWOW provided more suitable conditions for embryo development to the blastocyst stage when compared with cWOW or even WOW-PDMS. Among some possible reasons include the physical advantage of a smaller microwell that may better mimic the constraining effect of the zona pellucida on the developing embryo. That may also provide greater blastomere stability, favouring the aggregation state during the first rounds of cleavages, also aiding compaction and subsequent cavitation. The narrower microwell system appeared to have promoted better in vitro development than the conventional and the DMPS-based microwell systems, with no impact on subsequent in vivo development. However, the IVC in the WOW-PDMS system supported reasonable rates of development, in accordance with the current literature. Table 1.In vitro development of bovine IVF and cloned embryos produced after the in vitro culture in distinct IVC systems


2013 ◽  
Vol 25 (1) ◽  
pp. 296
Author(s):  
K. Nakano ◽  
M. Watanabe ◽  
H. Matsunari ◽  
T. Matsuda ◽  
K. Honda ◽  
...  

Porcine induced pluripotent stem (iPS) cells are considered to be an invaluable research tool in translational research with pigs as a large animal model. Pluripotency of the iPS cells needs to be verified by their competence to contribute to chimera formation. The aim of the present study is to establish feasible system to create chimeric pig fetuses using parthenogenetic embryos. In Experiment 1, inner cell mass (ICM) was isolated by immunosurgery from Day 6 blastocysts obtained by parthenogenetic activation of in vitro matured (IVM) oocytes. Isolated ICM were used as the donor cells after staining with fluorescent carbocyanine dye (DiI). Using parthenogenetic morulae or 4- to 8-cell embryos as the host embryos, chimeric embryos were prepared by injection or aggregation method. Injection of ICM was performed by micromanipulation: a single ICM was directly injected into the centre portion of the host morulae. In the aggregation method, a single ICM was aggregated with blastomeres isolated from 2 host embryos at the morula or 4- to 8-cell stage in a micro-well (400 µm diameter, 300 µm deep). The chimeric embryos were cultured in PZM-5 (Yoshioka et al. 2008) for 2 to 3 days to examine development to blastocysts and incorporation of donor ICM cells into the resultant blastocysts ICM (ICM chimerism). In Experiment 2, donor blastomeres isolated from a parthenogenetic morula or 4- to 8-cell embryo were stained by DiI and aggregated with a parthenogenetic host embryo at the morula or 4- to 8-cell stage, and the in vitro development to the blastocyst stage and the ICM chimerism were examined. In Experiment 3, ICM isolated from IVF blastocysts harboring humanized Kusabira-Orange (huKO) gene were used as donor cells. Donor ICM were aggregated with the host embryos at the morula or 4- to 8-cell stage, and the resultant blastocysts were transferred to 4 recipient gilts to collect fetuses on Day 18. Results of Experiments 1 and 2 are summarised in Table 1. Combination of the donor ICM and host morulae yielded high rates of blastocyst formation (~95%) and ICM chimerism (~85%), regardless of the method used (injection or aggregation). Transfer of 73 blastocysts developed from host morulae to 2 recipients (Experiment 3) gave rise to 25 (34.2%) fetuses, of which 6 (24.0%) were confirmed to be chimeric by their clear orange fluorescence and immunostaining by anti-huKO antibody. Of 22 (40.7%) fetuses obtained after transfer of 54 blastocysts derived from 4- to 8-cell host embryos to 2 recipients, 3 (13.6%) were chimeric. Contribution of the donor cells in the tissues of the chimeric fetuses measured by image analysis software (ImageJ, NIH, Bethesda, MD, USA) ranged between 16.1 and 65.2%. These results demonstrate that the aggregation method using parthenogenetic host embryos is an efficient means to produce chimeric pig fetuses, and thereby feasible for verification of pluripotent cells such as iPS cells. Table 1.In vitro development of injected or aggregated porcine embryos


2005 ◽  
Vol 17 (2) ◽  
pp. 162
Author(s):  
S. Akagi ◽  
B. Tsuneishi ◽  
S. Watanabe ◽  
S. Takahashi

It has been reported that aggregation of two nuclear transfer (NT) mouse embryos shows an improvement in full-term development (Boiani M et al. 2003 EMBO J. 22, 5304–5312). In this study, we examined the effect of aggregation on in vitro development of bovine NT embryos. As donor cells for NT, cumulus cells of passage 3–5 were used following culture in serum-starved medium for 5–7 days. NT was performed as previously described (Akagi S et al. 2003 Mol. Reprod. Dev. 66, 264–272). NT embryos were cultured in a serum-free medium (IVD-101, Research Institute of Functional Peptide Co., Ltd., Shimojo, Yamagat, Japan). Eight-cell-stage embryos on Day 2 or 16- to 32-cell-stage embryos on day 4 were used for embryo aggregation after removal of the zona pellucida. A small depression was made in a 25-μL drop of TCM-199 with 50 μg/mL phytohemagglutinin (TCM199/PHA) or IVD-101 using a darning needle. Two or three NT embryos were placed into the depression in the drop of TCM199/PHA for 20 min. NT aggregates were then moved into the depression in the drop of IVD-101 and cultured until Day 7. In vitro development of NT aggregates was summarized in Table 1. There were no differences in the cell number and ICM ratio of blastocysts between non-aggregated zona-intact and zona-free embryos. All aggregates of three NT embryos developed to the blastocyst stage and the cell number of these blastocysts was significantly higher than that of non-aggregated NT blastocysts. These results indicate that removal of the zona pellucida does not affect the cell number and ICM ratio of blastocysts and that aggregates of three NT embryos can develop to blastocysts with high cell numbers which are equivalent to in vivo-derived embryos (166 ± 11, Knijn HM et al. 2003 Biol. Reprod. 69, 1371–1378). Table 1. Development, cell number, and ICM ratio of NT aggregates


2017 ◽  
Vol 14 (4) ◽  
pp. 1309-1313
Author(s):  
Y. Al-Anazi ◽  
M. G. Al-Mutary ◽  
M. M. Alfuraiji ◽  
M. Al-Ghadi ◽  
A. R. Al-himaidi ◽  
...  

The aim of this work was to investigate the impacts of ram breed on in vitro embryo development from fresh or frozen semen. Semen was collected from Najdi and Naimi rams and frozen; the mass and progressive motility of the spermwere assessed in each trial before and after freezing. Then, 970 oocytes in six replicates were fertilized with fresh and frozen semen in vitro. Different stages of sheep embryos were recorded. There were no significant differences in mass and progressive sperm motility of fresh or frozen ram semen between Najdi and Naimi,but there were significant differences between frozen and fresh semen within each breed. Our results showed significant (P<0.05) differences in 2-cell stage, 4-cell stage, 8-cell stage, morula, fragmented embryos, cleavage and blastocyst rates in the frozen semen group compared to fresh semen group in both breeds. In addition, significant (P<0.05) differencesbetween the two breeds were shown in 8-cell and16-cell embryonic stages.In conclusion, there were slight breed effects on the efficiency of in vitro development of sheep embryos.


2006 ◽  
Vol 18 (2) ◽  
pp. 194 ◽  
Author(s):  
A. T. Palasz ◽  
J. Beltrán Breña ◽  
P. De la Fuente ◽  
M. F. Martinez ◽  
A. Gutiérrez-Adán

We have previously shown that bovine embryos cultured in SOFaa (BME + MEM amino acids) culture medium with hyaluronan (HA) + BSA are of better quality (Guti�rrez-Ad�n et al. 2005 Reprod. Fertil. Dev. 17, 219). Our objective was to examine the effect of essential (BME) or non-essential (MEM) amino acids with or without HA (MAP-5; Bioniche, Inc., Belleville, Ontario, Canada) on bovine embryo in vitro development and mRNA transcription of five developmentally important genes; apoptosis (Bax), growth factor (IGF-II), glucose (Glut-1) and fructose (Glut-5) transport and metabolism, and cell to cell adhesion (Cx-43). A total of 1474 presumptive zygotes (5 replicates) were initially cultured in 40 �L drops in the following groups: Group 1, control, SOFaa; Group 2, SOF-1 (MEM only); and Group 3, SOF-2 (BME only). On Day 4 (~96 h post-insemination (pi) the number of zygotes that had developed to d8 cells was recorded and 10 �L of SOF-1 and SOF-2, each with 2.5 mg/mL HA, was added to half of the embryos from Groups 2 and 3, respectively; the other half of Groups 2 and 3 and control group received 10 �L of corresponding medium without HA. Embryos were cultured under paraffin oil at 39�C and 5% CO2 in humidified air. Cleavage rates were recorded on Day 2 and the number of blastocysts on Days 7, 8, and 9. Five blastocysts from each replicate from each treatment were frozen for determination of gene expression patterns later. Cleavage rates and embryo development 96 h pi were compared among groups by chi-square analysis. The effects of HA and medium on blastocyst rates were analyzed by logistic regression and the data on mRNA expression by one-way repeated-measures ANOVA. Cleavage rates were 81.1% in SOFaa and 79.3% in SOF-1 (P = 0.48) and different from those in the SOF-2 group (72.4%; P < 0.02). The proportion of embryos that developed to d8 cells at Day 4 was higher in the control (46.7%) and SOF-1 (46.8%) groups than in the SOF-2 group (32.6%). The number of blastocysts that developed in SOFaa (37.0%), SOF-1 (37.7%), and SOF-1 + HA (37.8%) were higher (P < 0.001) than those in SOF-2 (19.6%) and SOF-2 + HA (21.8%). The level of expression of Glut-5 was not different among the groups. However, SOF-2 was the only group that had significantly lower expression of Glut-5, Igf II, and Cx43, and higher expression of BAX (P < 0.05) as compared to the control group and the SOF-1 groups with or without HA. Addition of HA to SOF-2 medium increased expression of Glut-1 and Igf II and decreased expression of BAX as compared to the SOF-1 only and control groups and the SOF-2 groups with or without HA (P < 0.05). The level of expression of Cx43 was higher in the control than in four remaining groups, and lower in the SOF-2 than in the SOF-1 group (P < 0.05). Addition of HA increased expression of Cx43 in both SOF-1 and SOF-2 groups but this level of expression was lower than in the control group; the level in the SOF-2 + HA group was lower (P < 0.05) than in the SOF-1 + HA group. We conclude that, within our protocol, MEM amino acids only stimulate embryo development to the blastocyst stage and the addition of HA to the SOF-MEM and SOF-BME media on Day 4 of culture improved embryo quality.


2006 ◽  
Vol 18 (2) ◽  
pp. 125
Author(s):  
M. Fahrudin ◽  
K. Kikuchi ◽  
N. W. K. Karja ◽  
M. Ozawa ◽  
T. Somfai ◽  
...  

The combination of bulk enucleation and zona-free cloning will offer simplification of the conventional nuclear transfer technique. A bulk enucleation method such as enucleation by centrifugation could reduce the time of manipulation that is necessary for removing genetic materials from the oocytes. The present study was conducted to examine the ability of cytoplasts obtained by centrifugation of zona-free in vitro maturation (IVM) porcine oocytes to support remodeling of the somatic cell nucleus and the subsequent development in vitro of somatic cell nuclear transferred (SCNT) embryos. A primary culture of cumulus cells was used as the source of donor cells, and recipient cytoplasts were derived from IVM oocytes that were cultured for 48 h, denuded of zonae pellucidae, and subjected to gradient centrifugation in Percoll solution to separate the ooplasm into fragments. Fragments were stained with Hoechst-33342 and cytoplasts were selected under an epifluorescence microscope. Then two or three cytoplasts were aggregated with a single somatic cell in phytohemagglutinin solution (500 �g/mL). Fusion between somatic cell and cytoplasts was induced by two DC pulses of 1.5 kV/cm for 20 �s, and activation was accomplished by two DC pulses of 0.8 kV/cm for 30 �s at 1 h after fusion in 0.28 M mannitol solution supplemented with 0.05 mM CaCl2 and 0.1 mM MgSO4. The resultant embryos were transferred to a WOW culture system (Vajta et al. 2000 Mol. Reprod. Dev. 55, 256-264) and cultured in glucose-free NCSU-37 containing 4 mg/mL BSA supplemented with 0.17 mM sodium pyruvate and 2.73 mM sodium lactate from Days 0 to 2; from Days 2 to 7 they were cultured in NCSU-37 supplemented with 5.55 mM {D}-glucose and 5% FCS. Some of the reconstructed embryos were fixed at 1, 10, and 24 h after activation and stained with 1% (w/v) orcein to display the morphology of the transferred somatic nuclei. The results showed that 53.6% (30/56) of the SCNT embryos underwent premature chromosome condensation at 1 h, 90.9% (50/55) formed pseudo-pronuclei at 10 h, and 21% (19/90) of them cleaved to the two-cell stage at 24 h after the activation. The development to the blastocyst stage of the embryos that were reconstructed by quartet cells (three cytoplasts and one somatic cell; 8.9%, 10/112) was significantly higher (P < 0.05) than that of the triplet ones (2.2%, 3/139). However, these blastocyst rates were significantly lower (P < 0.05) than the blastocyst development rate of parthenogenetic embryos with the intact zonae pellucidae (28.3%, 17/60). These results suggest that (1) cytoplasts obtained by gradient centrifugation could support reprogramming of somatic cells and in vitro development of SCNT embryos to the blastocyst stage, and (2) the volume of cytoplasts apparently affects their in vitro development in pigs.


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